Signaling device



March l5, 1932. LANGMUlR y 1,849,842

S IGNALING DEVI CE Filed Apri-1 5, 1930 Inventor: ITN/U12 Lamgmutr,

bk] v FILS Attofne.

Patented Mar. 15, 1932 IRVING LANGMUIR, F

scnENEcrAnY, NEW YORK, Assrenon 'ro GENERAL rimontare COMPANY, A CORPORATION 0F NEW YORK' SIGNALING DEVICE Application mea p My invention relates lto electric' flashing devicesl I have found that flashing devices such as I propose are more effective in guiding airplapnes to their landing fields or along `j their routes, in murky or foggy weather, than other types of signals, such as the ordinary rotating beacon.

In connection withmy invention I contemplate providing electrodes serving as the terminals of a circuit, means for periodically bringing the electrodes together to close the circuitand for thereafter separating them to produce iiashes periodically. It is also an object to provide in this circuit a reactance coil and an electromagnet in series, the former for restrictmg the rate of rise oi current in the circuit when it is closed and also for prolonging the flash and the latter for operating a mechanism to break both the circuit and the are formed after the' break. t

As a source of current for the flasher a storage battery may be used or instead a `motor generator set may be used where the main lsource of rent line. In such a case it is preferable that a flywheel shouldbe attached to the motor generator set, the object of the flywheel belng to modify the eiect on the power line of the closure of the electrodes preceding the flash. In place of a motor generator, however, a rectifier may be used such as a mercury pool full wave rectifier.

The nature4` and scope of the invention will be better understood from the following specification and claims, reference being had to the accompanying drawing for a specific illustration of the application of the invention. It will be understood however that I do not restrict the invention' to the particular form of apparatus and circuit `shown and described. but contemplate variations vand modifications as indicated by thescope of theclaims contained herein.

Referring more in detail to the drawing which shows the apparatus of the invention 1n diagrammatic form, the primary windin 2 of a transformer is vconnected to any suita le source of alternating current such as anor- 50 dinary alternating current power line repreprix 5,.

together with a pair .of

power is an alternating cur- 1830. serial No. 441,983.

sented by the terminals 2. The secondary winding 4 of the transformer is connected with the plates 8 and 9 of a rectifier 7 preferably of the so-called mercury pool type. The winding 4 is provided with a mid-terminal 10 from which a conductor 11 leads to a reactance coil 12 and through the reactance coil to an electromagnet orelectroresponsive switching means 134 terminating finally in the positive electrode 14 of thev flasher. The third terminal 15 of plate 6 or mercury pool of the rectifier is connected with conductor 16 which latter leads to an armature 17 of an electromagnet 18 on the endv of which armature the negative electrodek 19 is located. At least one of the electrodes, in the present instance the negative electrode, is mounted for movement relative to the other electrode such a distance that an arc formed between them is broken. In the present instance I have indicated armature 17 as being biased to its open circuit position by the provision of a biasing means or spring 17 a. The armature 17 is so placed that when the electromagnet 18 is energized the electrodes 14 and 19 are brought into Contact and the circuit closed through the reactance coil'12 and through the solenoid magnet 13. The reactance coil 12 is inserted inthe circuit to serve as an energy storing -means and for restrict'- ing the rate of rise of current thereby avoiding any undesirable fluctuations of voltage in the line The reactance coil also unctions to prolong and intensify the arc.l

Associated with the core 20 of the solenoid 13 is a latch 21 under the control of an electromagnet 22. When cuit of the electrodes determined amount, peres, the'core 20 of the solenoid is raised, due to the action of the operating coil of the electro-responsive switching means 13 in the main circuit. After thecore is raised it is caught and held by the latch 21 in the raised position. The rs olenoid 13 controls a switch 23 which, when the solenoid is energized, is opened,

14 and 19 reaches a' prethe current in the cirl as for example 200 am- 'i thereby breaking the -auxv iliary circuit through the electromagnet 18 *c may be dissipated inone-tenth of a'second.

I switch 24 the electromagnet In series with the electromagnet 18 I pro-v vide a switch 24 which is adapted to be closed for energizing the magnet 18, current being supplied for this purpose from any suitable source of current such as the line 25.

This source of current may for example be an ordinary 110 volt alternating current light `inv the coil 12 is added to that ofthe rectifier and the energy stored in the circuit is dis- Sipated at the arc at the time of the Hash.

The electromagnet 22, as indicated, is controlled by an automatically operated circuit interrupter 26 which periodically closes the circuit for the `magnet 22 each time that the arm 27 engages the contact 28. The energization ofthe magnet 22 unlatchesthe core 20 of the solenoid 13, permitting this core to fall back, thus closing a the 'magnet 18. ing energiized again brings the electrodes together, t ereby, gain initiating the cycle of operations previously dcibed.' Electromagnets 18 and 22 and interrupter 26 form a means for periodically moving electrode 19 into engagement with electrode 14 and holding it in such engagement until released by action of electromagnet 1 3. With such apparatus therefore arc flashes may be'periodically produced between the electrodes 14 and 19.l These flashes.l may be produced at"suit able periods fas for exam le at periods of from three to five seconds w 'ch however may be varied byvarying the-rate of operation of the device 26. Also b varying the size of the reactance coil 12 t e'am'ount of ener that becomes available for the flash may e varied. The solenoid 13 may be set so'v that the Hash does not take place -until the flow of current through the electrodes reaches, as already indicated, 200 am res, which value of current may be reache at the end of an interval of two-tenths of a second if so deaired, depending upon the character of the .reactance coil 12. The voltage produced varied by va when the electrodes are separated is affected by the character of the reactance coil 12. Therefore, the character of the arc can be 'ng the reactance coil.

With a device of this sort it is possible with a choke coil of about one henry to obtain approximately 2500 candle seconds which in the circuit through This magnet upon becom,

This means an instantaneous candle power O f about 25,000 maintainedIover a period of one-tenth of a second; for obtaining this result the electrode 14 may be, for example, a rod or wire of iron or steel about T16 in diameter. The terminal 19v may also be a rod of iron or steel, butI prefer to have it in the form of a block of iron. Electrodes of other,

material, however, may be used. In as much as the -flashing operation gradually consumes the electrode 14 this electrode may be mounted on any suitable feedin mechanism in order to maintain the end of electrode 14 approximately in a constant position 'with reference to the electrode 19.

When -a storage battery motor generator set is used the function of the reactance coil 12 as a means for delaying the rate of rise of the current in the circuit is not so important but it has another function, namely, Ythat of prolonging the arc and'of or a very large l th'us making it more effective which renders the coil important at all times.

acter the light source is not in any particular direction, but spreads in all'direc'- With a flashing device of the above'chardi tions and-is found to be more effective than when restricted to beam for What I claim as new and ldesire to secure by Letters Patent of the United States, is:

1. In va signaling device, a pair of electrodes, means mounting at least one of said electrodes for movement relative to the other such a distance-that an arc formed between them may be broken, means biasing said means to cause such movementa circuit for supplying current to said electrodes, an electro-responsive switching operating portion in said circuit and contacts separated on the of -a lpredetermined current throu llisaiil operating portion and latch means 01' holding the contacts separated, an electro-magnet cooperating with said mounting means to'move said electrodes into'contact, a secondary circuit including said magnet' and the contacts of the electro-responsive switching means, and

vmeans for tripping said latch meansto permit the closure of the secondary circuit.

2. In a signaling device, apair of electrodes, means mountingat least one of said electrodesxffor movementrelative to the other such ar distance that an arc formed between them maybe broken, means biasing said means to cause such movement, a' circuit for supplying j urrent to said electrodes, an electroponsive switching means having an Aoperatin portion in said circuit and contacts separat on the passage' of a predetermined current throu h said operating portion and latch means or holding the contacts separated, an electro-magnet cooperating with saidm'ounting means to move said electrodes into contact, a secondary circuit includi means having an f laid magnet and the 'contacts of the electrlh-g n responsive switching means, and means for periodically tripping said latch means to permit the closure of the secondary circuit.

3. In a signaling device, a pair of electrodes, means mounting at least one of said electrodes for movement relative-to the other such a distance that an arc formed between them may be broken, means biasing said means to cause such movement, a circuit for supplying current to said electrodes, means for periodically moving one electrode into engagement with thel other and for holding it in such engagement, electromagnetic means including a magnet in the electrode circuit for periodically moving one electrode into engagement with the other and for holding it in such engagement, electromagnetic means including a magnet in the electrode circuit forvrendering said holding means' inoperative on the increase of the current to a predetermined value, and a choke coil connected in. said c1rcu1t to increase the lntenslty and duration of the arc upon the separation of the electrodes.

In witness whereof I have hereunto set my hand this 4th day of April, 1930.

IRVING LANGMUIR. 

